1. Field of the Invention
The present invention relates to a thin film transistor (hereinafter referred to as a TFT) panel, a liquid crystal display (hereinafter referred to as an LCD) having the same, and a method of manufacturing the TFT panel, and more particularly, to a TFT panel for an LCD, which has an improved structure and a simpler and cheaper manufacturing process, an LCD having the same, and a method of manufacturing the TFT panel.
2. Description of the Related Art
Recently, LCDs have been widely used as display units.
In a liquid crystal display device, when a voltage is applied to a liquid crystal cell, a molecular arrangement of the liquid crystal is changed to cause a change in optical properties. As a result, visual properties are changed to display various images. A liquid crystal display device has various advantages, including lightweight and compactness. As a result, the liquid crystal display device is widely used for a monitor of a computer, a mobile communications terminal, and so on.
Liquid crystal display devices are divided into to a TN (Twisted Nematic) type and an STN (Super-Twisted Nematic) type. The liquid crystal devices are also divided according to the driving type into an active matrix display type that uses a switching device, and a TN liquid crystal and a passive matrix display type using an STN liquid crystal.
The active matrix display type is used in a TFT-LCD and drives an LCD by using a TFT as a switching device. The passive matrix display type does not use any transistor and does not need a complex circuit.
In particular, due to the expanding range of applications for active-matrix LCDs and tremendous growth in the number of users, new technologies for reducing the number of production process steps, reducing the manufacturing cost, increasing yield, and improving quality have been continuously developed.
Representative technologies that have been recently developed and widely applied are called a patterned vertical alignment (PVA) mode LCD and a color-filter on array (COA) mode LCD.
COA is advantageous in reducing the number of process steps and increasing the open ratio of an LCD panel by forming a color filter, which is conventionally formed on an upper panel, on a lower panel. However, COA is disadvantageous in that a process of forming the color filter on the lower panel requires high precision, expensive exposure equipment.
In addition, when red (R), green (G), and blue (B) materials used in forming the color filter overlap with one another, a step difference such as a protrusion occurs in a region in which red (R), green (G), and blue (B) materials are bonded to one another, and when a margin is reduced to prevent overlapping, a valley occurs in the bonding region, so that the quality of image information displayed on an LCD is lowered.